Guidugli, M. M B2014-05-262014-05-261984-12-01Revista de Geografia (Sao Paulo), v. 3, p. 77-85.http://hdl.handle.net/11449/63693The values attached to natural resources have changed through time because of changes in human needs as well as technological skill. Such changes become clear in the different forms of relationship which are established between man and nature. Man must discover more adequate forms of resources use, of obtaining new supply sources, and of recovering the last equilibrium.-from English summary77-85porArtigoAcesso restrito2-s2.0-0021538715